Cesar/android studio

[CesarValiente]

This Pull requests adds AndroidStudio/Gradle support.

The difference with https://github.com/spark/android-app/pull/11 is that this Pull Request manages just the gradle stuff to be able to work on Android Studio or IntelliJ.

I haven't changed anything related fonts, or libs to continue with the worflow Spark works (licenses stuff).

I've added the gradle wrapper for people who don't have a local gradle distro in their systems.

I've added jcenter/maven dependencies, but are commented for being able to download them remotely, but right now is commented because the original repo is using an old version of okhttp which uses an old way to open a connection (In a coming pr I will update that so we can use the latest OkHttp lib).

And the most important, since I haven't deleted anything that build.gradle can override on the manifests, the project can be used perfectly with eclipse too.

[CesarValiente]

Hi guys, any news here? :-)